To some people, it means that they probably don't feel a Hep vaccine is necessary on the date of birth or perhaps even for longer, because the parents will cont

To some people, it means that they probably don't feel a Hep vaccine is necessary on the date of birth or perhaps even for longer, because the parents will control the infant's environment. If you are taking your baby home, controlling who will touch the baby, what it eats, etc, Hep shouldn't be an issue, and the vaccine at day 1 seems like an unnecessary risk (even at 1000000:1 odds of an adverse reaction, the risk of infection may lower due to a newborn's lifestyle). That is just one example, but vaccine schedules are impacted by exposure risk, but also by some level of convenience (based on the fact that we don't go to doctors every day, so "let's vaccinate you as much as we can in the few times we'll see you"). If you show up for a well visit and your child is not 100%, do you let the child get the vaccine or do you come back next week/month? Vaccine safety is easier to test under very strict conditions and single vaccinations, but the topic is complicated by varying levels of child health as well as offering vaccines in combination.